facebook isSessionValid is always NO - iphone

Question

hi i use the newest facebook api with SSO and do implement like following in my viewController (not in the appDelegate like in the example if that makes any difference):
in my .h file
Facebook *facebook;
#property (nonatomic,retain) Facebook *facebook;
in my .m file i do the following in my viewDidLoad
self.facebook = [[Facebook alloc] initWithAppId:#"myappID"];
in another method I do
if (![facebook isSessionValid]) {
NSArray *permissions = [[NSArray arrayWithObjects:#"publish_stream",nil] retain];
[facebook authorize:permissions delegate:self];
}
but it seems that isSessionValid is alway NO
and I don't know why!
does anybody have any idea why ?
oh and also expirationDate and accessTokken are nil

Answer 1

I had this exact same problem yesterday, it seems you must persist and restore the access token/expiration date yourself.
In your viewDidLoad:
// Restore previously saved Facebook credentials (If any)
facebook.accessToken = [[NSUserDefaults standardUserDefaults] stringForKey:#"FBAccessToken"];
facebook.expirationDate = (NSDate *) [[NSUserDefaults standardUserDefaults] objectForKey:#"FBExpirationDate"];
// Trigger SSO Facebook authentication if required
if ([facebook isSessionValid] == NO) {
[facebook authorize:nil delegate:self];
} else {
[self fbDidLogin];
}
Then in the fbDidLogin delegate:
- (void)fbDidLogin
{
// Save the users access token and expiration date so we can restore it later
// This way we can avoid needlessly authenticating to Facebook.
[[NSUserDefaults standardUserDefaults] setObject:self.facebook.accessToken forKey:#"FBAccessToken"];
[[NSUserDefaults standardUserDefaults] setObject:self.facebook.expirationDate forKey:#"FBExpirationDate"];
// User has logged in to Facebook, now get their userId from Facebook
[facebook requestWithGraphPath:#"me" andDelegate:self];
}
So now users will have to login/authorize your application once and from then on their session will remain valid until they logout of Facebook.

Answer 2

alright here is the answer to my problem.
as I said in the comment also the application:handleOpenURL: never got called!
cause I had this method in my ViewController and apparently it has to be in the appDelegate!
so in my Navigationbar based application I did the following in my appDelegate:
in the .h file:
ViewController *viewController;
#property (nonatomic, retain) IBOutlet ViewController *viewController;
in the .m file:
#synthesize viewController;
viewController = [[ViewController alloc]init];
[self.navigationController pushViewController:viewController animated:NO];
and then implemented the method like that:
- (BOOL)application:(UIApplication *)application handleOpenURL:(NSURL *)url {
return [viewController.facebook handleOpenURL:url];
}
and of course in my ViewController I did everything #Tyler mentioned (thank you for that)
and everything works like a charm.
hope this helps everyone with the same problem.